The present invention generally relates to the rapid manufacturing of three-dimensional (3D) objects such as prototypes, tooling, and production-quality parts. In particular, the present invention relates to a method of surface treating rapid-manufactured 3D objects.
The production and testing of 3D objects is commonly used for developing new products, machines, and processes in a wide range of industries. There are a variety of rapid manufacturing techniques for building 3D objects, each of which develop the objects from geometric computer models under computer control. These techniques generally slice or divide a digital representation of a desired object (e.g., a computer aided design (CAD)) into horizontal layers, then build the object layer-by-layer by repetitive application of materials. The term “rapid manufacturing” herein refers to the building of 3D objects by one or more layer-based additive techniques. Exemplary rapid manufacturing techniques include fused deposition modeling, ink jetting, selective laser sintering, and stereolithographic processes.
3D objects built by rapid manufacturing techniques generally exhibit “stair-step” appearances, particularly at curved or angled exterior surfaces. The stair stepping effect is caused by the layering of cross-sectional shapes that have square-edge profiles, and is more pronounced as layer thicknesses increase. While the stair stepping effect generally does not affect the strengths of the 3D objects, it may significantly diminish the desired aesthetic qualities. A variety of polishing techniques have been used to improve the surface finish of rapid-manufactured 3D objects. However, there is an ongoing need for surface treatment techniques that provide aesthetically pleasing surfaces to rapid-manufactured 3D objects.